Investigation of growth indices of all female and mixed sex diploid and triploid rainbow trout Oncorhynchus mykiss in the second year of culture

In present study, weight related indices of growth including final weight, weight gain, specific growth rate and mean daily growth, were analyzed in all female triploid rainbow trout in compare to all female and mixed sex diploid and triploid populations during a period of 365 days in the second year of culture. Results of sampling of more than 4500 cultured fish indicated that growth increase of all female triploid rainbow trout was significant in compare to the other treatments (P > 0.05) and this growth advantage was more obvious as the experiment approached ending. At the end of culture period, mean final weight of all female triploid and mixed sex triploids reached up to 624.28 and 569.4 grams respectively, while these were 537.5 in all female diploids and 520.8 grams in mixed sex diploids. In conclusion, as the growth advantages of all female triploid rainbow trout were achieved in the second year of culture due to not occurring of sexual puberty, their culture could be recommended for fish culturists who are interested in fish growth over 300-400 grams of weight and want to land bigger fish to the market, considering the economic benefits of the fish production and nutrition.